Heat Pump Tumble Drier - air/heat output

Chickereeeee

I currently have a 15 year old Miele condenser tumble drier. The hot air output is low down on the front. This was not previously a problem on our tiled floor, but has caused the vinyl in our new kitchen to lift. (The floor temperature measures 35⁰C…).

Can anybody who has a newish heat pump tumble drier tell me:

Is the large vent (on the front of most) for air output or input?

If output, what sort of temperature is it at?

As a heat pump drier recycles both air and heat, I would expect little of either heat or air to be expelled, but I want to make sure, and they do have that large vent… (Local shops don't seem to know).

Thanks

mark_cycling00

I believe the principle is the same for both types but that the heat pump uses a reverse refrigeration process to create the heat. I might be wrong.

In the last 15 years these appliances have become much more efficient and lose much less heat and operate at lower heat levels too.

I had a Hotpoint heat pump dryer which was rubbish and overheated the circuit board after a year. The Bosch replacement is much much better.

I wouldn't say that any hot air comes out if it but if you fill it with bedlinen and towels that get tangled up then there can be some warmish, slightly moist air in the vicinity but not something that you can feel coming out of a vent.

MyRealNameToo

I've not studied it but have walked past our Miele heat pump one in the cold bare legged and dont remember feeling any material heat. A little along we have the exhaust from out in hob extractor fan and certainly feel warm air from that when walking past and its in operation.

They are predominately a closed loop system so the heat is recycled back into the drum rather than lost via vents which is why they are so energy efficient.

Behind the vent at the front is a big block of foam, often get messages about having to clean it which is annoying. So it's an intake not an exhaust.

ic

Heat pumps tumble dryers keep the air inside and recycle it which is why its important to clean the fluff filter frequently (ideally after every run). They also run at lower temperatures (hence longer run times). I wouldn't say ours noticeably warms the room - certainly there's a little humidity, but not much.

MyRealNameToo

https://forums.moneysavingexpert.com/discussion/comment/81921953#Comment_81921953

I've found ours is vastly quicker than the old condenser one it replaced (though it was a washer dryer).

I imagine vented would be quicker but the OP has condenser they say.

Chickereeeee

Thanks for replies.

Yes, the principle is that that is actually no 'heater' as such as I understand t - a compressor/expander(?) combination heats and cools the air on a cycle.. So there is no heat to get rid of.

'MyRealNameTwo' says the large front vent is an intake - which is what I believe, but it does beg the question - Where's the outlet?

ic

https://forums.moneysavingexpert.com/discussion/comment/81921992#Comment_81921992

TBH the same experience for me - only owned a washer dryer previously, which was fine for washing, but rarely used for drying. The heat pump dryer we have is far superior - and only takes a long time when run with a full load. Even then, it might two and half hours vs its initial predicted four and a half hours. Our washer is large capacity with 1400 spin speed, so washing is pretty dry before it goes in the dryer anyway.

sk2402005

I have a heat pump drier.

It doesnt get anywhere near as hot as the previous condencer it replaced, as its not really adding much heat to the room, heat that does escape, gets sucked back in as it scavenges heat from the room.

Also drying tempertures are much lower, this does extend the dryign time though.

Chickereeeee

https://forums.moneysavingexpert.com/discussion/comment/81928199#Comment_81928199

Thanks.

Can you confirm if the large front vent is input, output (or both) and if any output is significant in volume or heat, please?

This would help me in positioning of the dryer.

MyRealNameToo

https://forums.moneysavingexpert.com/discussion/comment/81922169#Comment_81922169

There is no material flow of air full stop, thats the whole idea. Its ultimately still a condensing tumble drier but whereas a condenser removes the hot wet air, dries it and pushes it out of the machine a heat pump effectively instead puts the now dried warm air back in so is a closed loop system.

The front vent is for the very modest amount of air used to cool the condenser but once the device is in full swing most the heat of the condenser is used to heat the air to be pushed back into the machine rather than wasting it venting it out of the machine.

Chickereeeee

https://forums.moneysavingexpert.com/discussion/comment/81930595#Comment_81930595

Thanks, yes that was my understanding, but I just needed confirmation that it was the case.

I presume they need such a large vent because they are relying on 'natural' airflow, ratherr than a fan.